Related

In the days leading up to the Boston Marathon, race officials had their eyes carefully trained not just on finish line preparations but the weather forecast. With temperatures in Boston expected to peak as high as 86 degrees Monday, organizers are cautioning inexperienced runners and those with medical problems to consider sitting this one out. They’ve offered any concerned racers a deferment – the option to stay on the sidelines this year and get guaranteed entry to next year’s race.

“This is not a day for personal bests,” Pierre d’Hemecourt, one of the race’s medical directors, said at a Sunday press conference. He recommended that runners consider a slower pace than normal and stressed the dangers of heat stroke that ramp up exponentially during heavy exertion. And the warnings on the Boston Athletic Association’s website are even more harrowing. “If you choose to run, run safely above all else. Speed can kill.”

This year, there’s a registered field of 26,716 runners, and Communications Director Marc Davis told TIME that 22,426 crossed the starting line this morning, though it wasn’t yet known how many would take advantage of the deferment offer. For those that did decide to run, concessions are being offered. The course will be open for an extra hour, until 6 p.m., to encourage runners to take their time (the race began at 10.00am in Hopkinton). And Race Director Dave McGillivray noted that organizers were bringing in double the amount of water on the course and were ramping up the number of emergency staff to deal with potential problems. “Only the fittest runners should consider running. The risks that you’ll see tomorrow are simply greater than normal,” said the athletic association’s executive director Tom Grilk.

It’s an unexpected volte-face for the race that just last year saw Geoffrey Mutai cross the finish line in a worldwide record time of 2:03:02. To be sure, conditions in 2011 – 50 degrees with a strong tailwind – were ideal on the mainly downhill course. Mutai, who is competing again this year, told the Associated Press that he’s never run a hot marathon, though the Kenyan runner is used to training in temperatures upwards of 70 degrees F. But the temperatures should be a cause of concern, even for elite runners, who have to worry about staying hydrated, perhaps making a number of inconvenient pit stops along the route. Race organizers come well armed with an arsenal of precautions after the last extreme weather situation back in 2004, when Boston saw 85-degree temperatures on the annual Patriot’s Day race. On that occasion, more than 2,000 out of the 18,000 runners sought medical attention. But despite the deferment and extra supplies offered, McGillivray still stressed the importance of personal responsibility during the race. The Boston Marathon hasn’t had an on-course death since 2002.

For amateurs who were intending to be competitive, the chance to postpone may well be an appealing option. But a number of devoted runners who spoke to Boston television stations before the race Monday morning seemed more enthused about running for the love of the sport, not for breaking records. “We’ll run a little slower, but we’ll be fine,” Allyne Winderman told Boston.com. After all, she reminded us, Honolulu has an annual marathon too. But Hamish Coleman had perhaps the best idea: “I’m just looking forward to having a few cold beers afterward.”